Pilot for valve seat facing tools



March 14, 1939. E HALL 2,159,621

PILOT FOR VALVE SEAT FACING TOOLS Filed June (5, 1938 Patented Mar. 14,1939 t. I

UNITED STATES PATENT QFFICE A PILOT FOR V I VE SEAT FACING TOOLS ErnestA. Hall, Toledo, Ohio, assignor to The Hall Manufacturing Company,Toledo, Ohio, a corporation of Ohio Application June 3, 1938, Serial'No.211,702

4 Claims. (Cl. 51-241) This invention relates. to grinding or facing Inthe present instance, each guide is provided means for the valve seatsof internal combustion with a bearing sleeve 4 in which the valve stemengines, and particularly to a pilot for use in operates. Such sleevemay, however, be omitted, connection with such a means, especially whenas is frequently done, and the opening through 5 employed in connectionwith the valve seats of the guide 3 may alone serve as the valve stemradial type aeroplane engines, or those having guide. It will beunderstood that the term angularly arranged valve seats in the head.guide, as used in the description and claims,

The pilot customarily-employed in connection means the valve stem guideopening formed with valve seat grinders are each inserted into a eitherby the guide 3 or the sleeve 4 mounte valve stem guide through the valveseat opentherein. 10

ing from the cylinder side of the guide and then The pilot embodying thepresent invention secured from without the guide tocenter the pilotcomprises a stem I0, an expanding bushing II therein. With engines ofthe angular seat or mounted on the stem and adapted to be inserted vradial aeroplane type, this is ordinarily impossiinto the guide opening,and an adjustable nut ble, or at least impractical, due to the length ofmember I2 cooperating with the outer ends of 15' the pilots and smalldiameters of the cylinders, the stem I0 and bushing II in a manner tocause and it is therefore necessary to provide a pilot relative axialmovements thereof when the memfor use in connection with such engineswhich her I 2 is turned, as hereinafter described. may be inserted inposition through the guide The stem II] is of sufiicient length toProject at s from without the cylinder and then centered its inner endthrough the valve seat Opening therein. Inasmuch as the wear in mostvalve d a p edete distance into the Cylinder stem guides is at the ends,it is necessary to grip to beslidingly engaged by a grinding tool 5thereand center the pilot at both ends of a guide, as in, as wellunderstood in the art, and for its well understood in the art, and theadaptation outer end to project a distance without the outer of theordinary pilot for this purpose prevents end of the guide. The stem I 0intermediate its 25 its use where positioning through the guide fromends at the portion thereof disposed within the its outer end, insteadof through the cylinder, inner end portion ofthe guide is formed with isnecessary. an outwardly facing conical taper I3, the maxi- The object ofthe present invention is to provide mum diameter of which is of suitablesize to pass a pilot of the class described which is adapted to throughth guide Opening in the p esent be inserted in position through a valvestem guide instance, is app o the Size of the er from its outer end andhas simple and efficient nd Portion of the Pilot Stem- The Outer ndmeans for fixedly mounting the pilot in centered portion of the pilotStem, Which extends f m position therein. and is approximately thediameter of the small The invention is fully described in the followd oe t p is threaded w dly a dising specification, and one embodimentthereof anee from its Outer end at H- illustrated in the accompanyingdrawing, in y e bushing H is intended to fi u d the which-- portion ofthe pilot stem within the guide and Figure 1 is a fragmentary sideelevation of an is longitudinally split or slotted at its inner end,angular seat aeroplane engine cylinder, with a as at I5, to render suchend expansible, and has pilot embodying the invention mounted in operitsbore tapered at such end for coaction with ative position therein andbeing partly in central the stem taper I3. The opposite end of thebushlongitudinal section, and with avalve seat grinding I I is providedwith a conical taper I6 for er mounted on the pilot, with a part brokenaway; centering engagement with the outer end por- Fig. 2 is an enlargedside View of a pilot embodytion of the guide bore when forced therein,and is 45 ing the invention, with parts broken away; Figs. provided,without such taper, with a head I1, the 3 and 4 are enlargedcross-sections on the lines outer end of which has its bore enlarged toform 33 and 4-4 in Fig. 2, and Fig. 5 is a side view a socket I8. Theportion of the bushing II outof the bushing member of the pilot, withparts wardly from the small end of the taper I6 is of broken away.cylindrical form and of a size to substantially fit 5 Referring to thedrawing, I designates a cylthe valve stem guide opening. It ispreferable, inder of a radial type aeroplane engine, having however, toreduce the diameter of the bushing the angularly disposed valve seats 2in the head intermediate its split end and the taper I6, so and thecustomary valve stem guide 3 at the as to provide the bushing withaxially spaced cylouter side of each seat in axial register therewith.inder bearing portions I9. 55

The adjusting member I2 is of sleeve-form with its inner end threadedonto the threaded portion M of the pilot stem and is of suitablediameter at least at its inner end to rotatably fit into the socket I 8.The member 12 is held in rotatable engagement with the bushing II byreason of cross-strips 2B in the wall portion of the socket I8 engagingin an annular groove 2| in said member. The socket wall is slotted toform the strips 28 and these strips are pressed into the groove. Themember 12 may be provided at its rear end with a cross handle-bar 22 tofacilitate turning.

In mounting the pilot in a valve stem guide, preparatory to being usedas a guide means for a valve seat grinder 5, the pilot in its entireassembled form, as shown in Figs. land 2, is inserted through the guideopening to position its inner end in proper guiding position within thecylinder and to fit the conical taper I6 of the bushing il into theouter end of the guide opening, so as to center the bushing and stem atsuch point in the guide. This having been done, the nut member I2 isturnedyrelative to the bushing H and stem i!) to efiect a threadingthereof on the stem so as to draw the stem outward to force its taper l3into the coacting inner end of the bushing II. This action causes anexpansion of the split end portion of the bushing within the guideopening to firmly center the stem in its inner end. The guide is thusfirmly engaged at each end of its opening by the bushing i i andoperates to firmly hold the pilot stem in true centered relation to theguide and valve seat.

I wish it understood that my invention is not limited to any specificconstruction, arrangement or form of the parts, as it is capable ofnumerous modifications and changes Without departing from the spirit ofthe claims.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent, is:

1. A pilot of the class described having a stem portion adapted to beinserted through a valve stem guide from the outer end thereof andhaving an outwardly facing tapered portion intermediate its ends, abushing mounted on the stem and having its inner end portion split andin engagement with said tapered portion for expanding engagement withthe inner end portion of a guide opening inwhich mounted, said bushinghaving an inwardly facing outwardly spaced conical portion for engagingwithin the outer end portion of a guide opening in which positioned;

and means mounted on the outer end of said stem and operable to draw thestem taper into the bushing to expand its inner end.

2. A pilot of the class described comprising a valve stem adapted to beinserted into operative position through a valve stem guide opening fromthe outer end thereof and having an outwardly facing conical taperintermediate its ends, a bushing mounted on said stem without its taperand adapted to be inserted a predetermined distance into a guide openingwith the stem and havin its inner end expansible to firmly fit withinthe inner end portion of a guide opening and coacting with said taper;said bushing having an inwardly facing tapered portion in outwardlyspaced relation to its inner end to fit into the outer end of a guideopening, and an adjusting member threaded on the outer end of said stemin'thrus't coaction with the outer end portion of said bushing whereby aturning of the member in one direction on the stem will draw the stemtaper into the bushing to expand its inner end.

3. A pilot of the class described having a bushing for insertion into avalve stem guide opening from the outer end thereof, said bushing havingan expansible inner end portion and an inwardly facing tapered portionfor centering engagement within opposite end portions of a guide openingand having a socket in its outer end, a pilot stem mounted in saidbushing and adapted to be inserted through a guide opening with saidbushing, saidstem having an outwardly facing conical portion fittinginto the inner expansible end portion of the bushing; and means threadedon the outer end of the stem in coaction with the bushing and operablewhen turned on the stem to effect a drawing of the stem taper into thebushing.

4. A pilot of the class described having a bushing for insertion into avalve stem guide opening from the outer end thereof, said bushing havingan expansible inner end portion and an inwardly facing tapered portionfor centering engagement Within opposite end portions of a guide openingand having a socket in its outer end, a pilot stem mounted in saidbushing and adapted to be inserted through a guide openingrwith saidbushing, said stem having an outwardly facing conical portion fittinginto the inner expansible end portion of the bushing, and means threadedon the outer end of said stem and being anchored in said bushing socketto permit relative rotary movements and prevent relative axial movementsthereof.

ERNEST A. HALL.

